Fluid-pressure brake.



W. V. TURNER.

FLUID PRESSURE BRAKE.

APPLICATION FILED MAR. 9. I911.

Patented Oct. 15, 1918.

4.6 INVENTOR Walmr Turner? WALTER V. TURNER, F WILKINSBURG,PENNSYLVANIA, ASSIGNOR TO THE WI JSTING- HOUSE AIR BRAKE COMPANY, OFWILMERDING, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

Specification of Letters Patent.-

rnurn-rnnssunn BRAKE.

Application filed March 9, 1917. Serial No. 153,544.

To all whom it may concern:

Be it known that I, WALTER TURNER, a citizen of the United States,residing at Wilkinsburg, in the county .of Allegheny and State ofPennsylvania,

have invented new and useful Improvements in Fluid-Pressure Brakes, ofwhich the following is a speclflcation. 1

This invention relates to fluid pressure brakes, and more particularlyto an automatic fluid pressure brake system.

In an automatic fluid pressure brake, valve devices are employed inwhich there is a piston subject to the opposing pressures of the brakepipe and a chamber, adapted to be charged from the brake plpe, such astriple and brake pipevent valve devices.

With a device of the above character,-

when the brake valve is turned to full release position,

chamber of the valve device to a higher degree of pressure than is thecase farther back in the train and thebrake valve is then turned torunning position, the re duced rate of flow to the brake pipe is apt toproduce such a diflerential pressure between the chamber and the brakepipe on i the valve device at the head end, as to cause same to move toemergency position when not intended.

The principal" object of my invention is to provide means for preventingmovement of a valve device of the above character to emergency positionvunder fluctuati0ns 'in brake pipe pressure produced in releasing thebrakes, while insuring emergency action casing'having a valve chamberG-containing a brake pipe vent valve 7 for venting fluid from brake pipepassage 2 through a passage 8 to an exhaust passage 9. The vent fluid issuppliedto the brake pipe v at a rapid rate which is liable to chargethe a. diagrammatic view, mostly in valve 7 is adapted to be operated bya quick action piston 10 contained in piston chamber 11 which is"connected to apassage 12, leadmg to the seat of an emergency slidevalve 13. 4

The emergency slide valve 13 is contained in a valve chamber 14connected by passage A 15 to a chamber 16 and is operated by a piston 17contained in piston chamber 18, which is connected by a passage 19 withvent valve 1 chamber 6 and consequently to the brake pipe. v

According to my invention, a cut ofl' check valve dev1ce 2Q is provided,comprising a casing containlng adouble seating check valve 21, havingthe chamber 22 at one side connected by pipe 23 with chamber 16 of thevent valve device and having chamber 24 at the opposite side connectedby pipe 25 with a cut out cook 26 interposed in the brake pipe. 3.

A spring stop 27 tends to maintain the check valve 21 in normalposition, as shown connects the chambers 22 and 24.

The brake valve device 5 may be of the usual construction having arotary valve 29 contained in valve chamber 30 connected by passage 31and pipe 32 with main reservoir 33 and adapted to be operated by ahandle 34 and may be provided with the usual fequallzing dischargepiston 35 subject on one side to the pressure of an equalizing reservoir36 and connected on the opposite side to brake pipe passage 4 andadapted to operate a discharge valve 37.

In operation, the cut out cook 26 being Patented (Pet. 15, rate,

in the drawing, in which aby-pass port 28' A turned to open pdsition atthe operating brake valve, upon initially charging the brake pipe, fluidis. supplied to the brake pipe and also through the branched passage 38of the plug valve 39 to pipe 25 and the check valve is thereby shiftedto its vent valve seat, closing the by-pass passage 28, so that fluidcan be supplied to the chamber 16 only through the vent valve device.

Fluid supplied through the brake pipe 3 to the vent valve device 1 flowsthrough pas sage 8, piston chamber 18 and thence through passage 40,past check valve 41 to passage 42 and valve chamber 14. Said valvechamber and chamber 16 are thus charged with fluid under pressure. p

If the brake pipe is charged at a high rate,

valve chamber 6, and passage 19 to as Where the brake valve is turnedto'release position, the valve chamber 1% and chamber 16 may becomeovercharged from the brake pipe, but this will do no harm, for accordingto my invention, upon movement of the brake valve to running position,when the rate of flow to the brake pipe is reduced, the higher pressurein chamber 16 acting in chamber 22 of the check valve device willovercome the lower brake pipe pressure inchamber 24, so that the checkvalve 21 will be shifted to engage the spring stop 27 and open theby-pass p0rt'28, thuspermitting the higher pressure in chamber 16 toequalize into the brake pipe. The accidental movement of the emergencypiston 17 to emergency position is thus prevented. If

, the rate of reduction in brake pipe pressure should exceed thecapacity of the bypassport 28 to reduce the pressurein chamber 16,the'piston 17 may be shifted to service position, in which the\pistonengages a spring-sto 43. In this osition, a port d4 in'the sli e valve13 registers with passage 45, leading to, exhaust passage 9, so thatfluid is vented from valve chamber 1%, to further assist in preventingthe movement of the emergency valve to emergency position, 1

Ifan emergency reductionin brake pipe pressure is efiected, the rate ofreduction is so rapid, that the capacity of the by-pass ,port 28 is muchexceeded, and the pressure in chamber 16 Will move the check valve 21 toits brake pipe seat against the resistance of the spring stop 27, thusclosin the bypass port, so that the pressure in va ve chamer 14 andchamber 16 is not reduced; ,and

as a result, the emergency piston 17 is shifted to emergency positionagainst the.

resistance of the spring .stop $3. In this position, the slide valve 13uncovers passage 12, so that fluid under pressure; is supplied fromvalve chamber 14; to quick action .pis-

ton chamber 11, operating the piston 10 so as to 0 en the vent valve 7and vent from the brake pipe to the exhaust passage 9. n

When the pressure in'valve chamber 14 and chamber 16 has reduced throughan equalizing port 46 in piston 10, to a prejdetermined degree, thequick action piston 10, Will return to normal position and the ventvalve 7 to the closed position.

It is not necessary to have theicut off check valve operate except nearthe opera v tive brake valve, and consequently, the brake pipeconnection to the check valve is made through the brake pipe cutout cook26, so that When the cut out cock is turned -to the closed position atthe non-operating brake valves, as is usual, the brake ipe is also cutoil from the cut of)? check va ve device.

-A by-pass pipe 47 around the cut-out cock sure for venting fluid fromsai menses 26 may be provided, so that in case the'cut out cock shouldaccidentally be left closed at the operating brake valve, an emergencyreduction in brake pipe pressure throu h the by-pass pipemay still beobtained, by manipulation of the brake valve.

2 Having now described my invention, what I claim as new and desire tosecure by Letters Patent, is 1-- 1; In a fluid pressure brake, thecombination with a brake pipe and a valve de vice subject tothe opposingpressures of .the brake pipe and a chamber, of means subject to theopposing pressures of the brake pipe and said chamber and operated upona reduction in brake pipe pressure for venting fluid from said chamber.

2. In a fluid pressure brake,-the combinationwith a brake pipe and avalve device subject tothe opposing pressures of the brake pipe and achamber, of a checkjvalve device subject to the opposing pressures \ofthe brake pipe and said chamber and 6p- 'erated upon a reduction inbrakepipe pressure for venting fluid from said chamber and upon a more rapidrate of reduction in brake ipe pressure for preventing the venting 0fluid from said chamber.

7 3. In a fluid ressure brake, the combination 'With a bra e pipe and a'valve device subject to the op osing pressures of the brakepipe and a camber, of a check valve device subject to the o osing ressures of thebrake pipe and sai cham er and operated upon a reduction in brake ipepresd chamber to the brake pipe. i

d. In a fluid pressure brake, the combination with a brake pipe and-avalve device subject to the opposing pressures of the bra e pipe and achamber adapted to be "charged from the brake pipe, of a ielding stopand a check valve device su ject to the opposing pressuresof the brakepipe and said chamber and operated upon a reduction brake ipe ressure toengage said stop and vent fluid rom said chamber and movable upon a morerapid reduction brake pipe pressure against the resistance of said stopto prevent the venting of fluid from said chamber.

5. In a fluid pressure brake, the coinbina adapted to be charged fromthe brake pipe, 13o

of means subject to the opposing pressures of the brake pipe and saidchamber and operated upon a reduction in brake pipe pressure for ventingfluid from said chamber and a brake pipe cut out cock for connecting thebrake pipe to said means and adapted in the closed position'to cut ofithe brake pipe therefrom.

7. In a fluid pressure brake, the combination with a brake pipe and abrake pipe vent valve device comprising a piston subject to the opposingpressures of the brake pipe and a chamber adapted to be charged from thebrake pipe and a valve operated by said piston for efi'ecting areduction in brake pipe pressure, of a check valve device subject to theopposing pressures of the brake pipe and said chamber and operated upona reduction in brake ipe pressure less than the emergency rate ofreduction for venting fluid from said chamber.

In testimony whereof I have hereunto set my hand.

WALTER V. TURNER.

